Vacuum filling machine



138,140,141, 143,145, 148-150, l55-l57, 159-160, 275, 277,198lnq 0 United States Patent 11113,542,090 72) inventor Edward J. McCarthy [56] References Cited 1 N 23 2;? Mmch'lseiis UNITED STATES PATENTS P 2,081,158 5/1937 Tamminga m1. 141/59 [22] F1led June 22, 1966 2,081,651 5/1937 Tammmgae t al. 141/59 [45] went 2 603 39s 7/1952 P h t 1 141 51x [73] Assignee Pneumatic Scale Corporation, er 6 a I 2,847,040 8/1958 McCarthy et al..... 141/5i omncyMasmhmm 3 254 683 6/1966 .iennin s t 1 l4l/l98X a corporation of Massachusetts g e a Primary Examiner- Laverne D. Geiger Assistant Examiner-Edward J. Earls 1 VACUUM FILLING MACHINE Attorney Robert R. Churchill 9 Claims, 6 Drawing Figs. [52] U.S. Cl. 141/59, 141/141 ABSTRACT: A vacuum operated filling machine for filling [51] int. Cl. B65b 57/02, bags made of flexible material and having bag operated con- B65b 31/04 trol means actuated by the upper edge of the bag for initiating [50] Field of Search 141/51, 59, a filling operation and consequently which prevents operation of the machine in the event of the absence or displacement of a bag.

"Patented Nov. 24, 1970 I of 6 Sheet INVENTOR Edward J.Mc Cort/7y Ww/fl wag ATTORNEY Patented Nov. 1970 3,542,090

Sheetv 2 of 6 I N VENTOR.

BY Edward JMc Carfhy ATTORNEY Patented Nov. 24, 1970 Q 3,542,090

w a m 3 co o :0 cu

( INVENTOR.

L: BY Edward J M0 Cart/2y ATTORNEY Patented 24, 1970 3,542,090

I Q Sheet Q of 6 Q F7 4 V INVENTOR.

BY Edward J McCarthy ATTORNEY Patentd Nov'.24, 1970 3,542,090

Sheet 5 of6 IN VENTOR.

BY Edward J. Mc Cart/2y fywemw ATTORNEY Patented Nov. 24, 1970 3,542,090

Sheet 6 of6 I INVENTOR.

BY Edward J McCa/fhy A 7' TORNE Y l the present invention;

. l vAcnu FILLING MACHINE simple and expedient manner.

With this general objectin view andsuch others as may hereinafter appear, the invention consists in the vacuum filling machine and in the various structures, arrangements and combinationsof parts hereinafter described and particularly defined in the claims atthe end of this specification.

In the drawings illustrating the preferred embodimentof the invention:

FIG. 1 is a plan viewof avacuum filling machine, embodying FIG. 2.is a plan view of the lower portionof the machine showing part of the control mechanism; 1

FIG. 3 is a developed view inside elevation of the filling heads and their elevatingplatforms and diagrammatically indicating portions of the cOntrOImechanism;

FIG. 4 is a diagrammatic view of the pneumatic and electrical controls associated with the filling heads;

FIG. 5 is a cross-sectional view of a vacuum filling head showing a container operated control valve associated therewith; and a FIG. 6 is a plan view of the drives tothe filling machine.

In general, the present invention contemplates a novel and improved vacuum operated'filling machine, herein shown as provided with shrouded vacuum filling heads, adapted to fill flexible containers, such as bags, with finely divided flowable materials and, in general, comprises an improvement in the vacuum filling machine illustrated and described in the U.S.

Pat. No. 2,847,040 to Edward J. McCarthy etaL, issued Aug. 12, 1958. Such prior machine comprises a continuously operated rotary machine having'a plurality ofelevating platforms arranged to .receive'. successive containers delivered thereto and to elevate the same into operative relationto the shrouded vacuum filling heads duringthe rotary movement of the machine. a

In the operation of the'present machine successive bags' are transferred onto successive elevating platforms by a rotary transfer spider which is arranged to engage'and transfer successive bags deliveredthereto by acon'tinuously operated convbag is lowered. with its elevating platform preparatory to discharging the bag from the machine. However, in the event that the bag becomes stuck in its shroud and is not lowered with its elevator, the container operated control remains in its actuated position beyond a predetermined point in its filling cycle. In such event, provision is also made for terminating the operation of the machine so that the operator may remove the stock bag'from the shroud.

In accordance with another feature of the present invention, provision is made for controlling the operation of the machine in a manner such as to' prevent elevation of a particular elevating. platform, in the event that a container is absent from the supply in a position to'be transferred thereto, while permitting the machine to continue in operation to fill and discharge the preceding and succeeding containers delivered thereto. By permitting continuation of operation of the machine production is increased and wear and tear caused by unnecessary or excessive stopping and starting of the machine is reduced to a minimum. In practice it will be seen that failure of the elevator torise because of the absence of a bag also fails to actuate the ,bag operated control means for that particular filling head so that filling operation is not initiated. Thus, the bag operated control means will remain in a position to discontinue operation of the machine, the same as when a bag fails to be fully seated. However, elevator operated control means actuated when the elevator fails to rise and remains in its lowered position is arranged to maintain the machine in operation in the event that a bag is initially absent as will be described.

Referring now to the drawings and particularly to FIG. 1, thepresent invention is illustrated as embodied in a rotary type machine having a plurality of elevating platforms 10 conveyor having provision foradvancing the bags in predetermined spaced relation and .in-timed relation to the rotary transfer spider. The? bags thus received on their respective elevating platforms are. elevated into operative relation to their respective filling heads rotated in alineinent therewith, and when a bag is fully seated and sealed in a vacuum filling head, the bag is evacuated and filled with the material being packaged. The elevating platform is then caused to be lowered with its filled bag. andtransferred from its platform onto a discharge conveyor i In accordance with one feature of the. present invention novel and improved bag operatedpneumatic control means is provided including means actuatedby the upper edge of a fully seated and sealed flexible bag for initiating the filling operation. Thus, if a bag fails to be fully seated in filling'position relative to its filling head,.indicating that the flexible bag is jammed or otherwise displaced in its shroud, the vacuum filling means remains inoperativefor that particular filling 'head. Also, in such event, means controlled by the bag 7 fully seated and sealed in its shroud and the filling operation is initiated by virtue of the bag operated control'means to fill the bag during the continuous rotation in a circularpath, the filled tinuously movable in a circular path and'arranged to support successive bags 12 delivered thereto by rotary transfer mechanism indicated generally at 14. As herein shown, the bags are supplied on a conveyor 16 along which they are advanced in spaced relation and in timed relation to be received by rotary transfer elements 18 which are arranged to continue the advance of successive bags onto successive elevating platforms 10. In general, in the operation of the machine the bags are elevated into operative to shrouded vacuum filling heads indicated generally at 20 rotated in alinement with the elevating platforms 10. The elevating platforms l0 are'arranged to seal the bags in airtight relation to the filling heads to permit evacuation and filling of the bags during the rotation of the machine whereupon the elevating platforms are lowered with theirfilledbags and transferred from the platforms by transfer means indicated generally at 22 to deliver successive bags onto a discharge belt 24.

As illustrated in FIG. 6, the drive to the rotary filling machine is taken from a motor driven lineshaft 26 which drives a lineof successive synchronized package forming,

opposed gears 44'and 46 for driving the continuously rotated intake and discharge spiders 14 and 22, respectively, of the continuously operated bag filling machine. A third gear 48in mesh with the intermediate gear is in mesh with a ring gear 50 for rotating the filling heads and elevating platforms of the bag filling machine. Successive bags 12 engaged by the transfer arms 18 are advanced between curved guide rails 52, 54 in timed relation to the arrival of successive elevating platforms 10 of the bag filling machine and the bags delivered to the platforms are then elevated into operative filling position to their respective vacuum filling heads 20. As shown in FIG. 1, the transfer arms 18 are pivotally mounted on a disk 56 fast on the intake spider shaft 58, and each arm is provided with a roller 60 for cooperation with a stationary cam 62 supported beneath thedisk. The cam 62 is designed to maintain the transfer arms 18 in their bag engaging position until the bag is deposited on its elevating platform whereupon the arm 18 is permitted to rock away from the bag to avoid displacement of the same on its elevating platform during the continuous rotation of the transfer arms and the elevating platforms.

As indicated generally in FIGS. 3 and 4, each elevating platform 10 is mounted on and secured to the top of a pneumatically operated sleeve or cylinder 64 slidingly supported on an upright post 66 secured to an annular plate 68 rotatable with the machine. The post 66 is provided with a central bore 70 which communicates with an air supply at its lower end and is closed at its upper end by the underside of the elevating platform 10 when the platform is in its lowered position. In operation, when compressed air is permitted to enter the lower end of the central bore 70, the sleeve 64 with its elevating platform 10 is caused to rise on its central supporting post 66 to elevate a bag into operative relation to its individual shrouded vacuum filling head. In general, the elevating means is similar to that shown and described in U.S. Pat. No. 2,847,040, above referred to except as to the control means to be hereinafter described. As herein shown, compressed air is supplied to each elevator through individual valve units 71 connected to a supply header or loop 73 rotatable with the machine, the header air. being'connected by a vertical pipe 75 extending to a point above the machine where the pipe is offset to extend in alinement with the center of rotation of the machine. The upper end of the vertical pipe 75 is provided with a stationary adapter 77 arranged to permit rotation of the pipe, and the adapter is connected by a supply pipe 79 to a regulated source of compressed air. Each individual valve unit 71 is provided with an arm 81 having a roller 83 for cooperation with control cams for opening and closing the valves to permit elevation and lowering respectively of the elevating platform as will be hereinafter more fully described. A conduit 85 extends from the valve unit 71 to the lower end of the elevator supporting post 66.

In general, the shrouded vacuum filling heads are also similar to those illustrated and described inthe patent above referred to except as to details to be hereinafter pointed out. As shown in FIG. 5, each filling head includes a head portion 72 provided with a material inlet opening 74 and with two suction openings 76 and 78. The head portions 72 are secured to the underside of an annular plate 80 which is in communication with an annular supply hopper 82 secured to the plate. Each filling head further includes a hollow rectangular shroud portion 84 slidingly supported in alinement with its head portion on rods 86 depending from the head portion. The upper end of the shroud portion is provided with a bag mouth engaging and sealing section section comprising a flexible band 88 of rubber or like resilient material, the band being cemented or otherwise secured to the upper end 90 of the shroud and to a separate rectangular hollow section 92 above the shroud leaving an intermediate preconvoluted connecting portion of the flexible band free. In operation, when a flexible bag 12 is elevated into the shroud portion of the filling head by the elevating platform 10, the upper edges of the mouth of the bag are guided into the relatively narrow space between the filling head portion 72 and the band 88, and upon further upward movement of the elevator 10, the band will be resiliently urged into airtight sealing engagement with the bag at a point below the upper edge of the bag. At the same time, the open bottom of the shroud will be sealed by engagement of the platform 10 with a resilient skirt portion 94 to enclose the bag within the shroud. As shown, there is a space between the interior of the shroudand the exterior of the bag, which space is also evacuated at the same time that the bag is evacuated so as to prevent collapse of the bag.

The vacuum filling operation is per formed in a manner similar to that illustrated and described in the patent above referred to wherein the fully seated and sealed bag in the shrouded vacuum filling head 20 is evacuated and filled, the vacuum being controlled by individual cam operated valve block units 96 associated with each vacuum filling head. As shown in FIG. 4, each valve block 96 is provided with a vacuum supply chamber 98 having a valve opening 100 in communication with a vacuum chamber 102. The supply chamber 98 is connected by a conduit 104 to a hollow cap member 106, see FIG. 1, rotatable about the upper end of a central hollow supporting sleeve, the lower end of which is connected to a vacuum pump or other source of reduced air pressure as shown in U.S. Pat. No. 2,847,040 to which reference may be made. The vacuum chamber 102 is provided 'with a conduit 108 connected to the head portion 72 and is also provided with a valve 110 slidingly mounted in the valve block 96 and arranged to close the opening 100 between the chambers 102 and 98. The valve 110 is connected to an air cylinder forming a part of the pneumatic control circuit for initiating the filling operation in response to bag operated sensing means as will be hereinafter described.

The vacuum chamber 98 is also provided with a valve 112 slidingly mounted in the block 96 and arranged to cooperate with a port 114 to which the vacuum supply pipe 104 is connected. The outer end of the valve stem is provided with a forked member 116 having a roller 118 arranged to cooperate with a cam 120 fast on the central supporting sleeve. A spring 122 surrounding the stem of the forked member 116 and interposed between the shoulder of the forked member 116 and the valve block 96 is arranged to urge the valve 112 to its open position, and the cam 120 is arranged to move the valve to its closed position to close the port 114 and to cut off the suction to the vacuum chamber 98.

The valve block 96 is also provided with an atmospheric chamber 124 which has an opening 126 and a port 128 connected by a conduit-130 to the vacuum filling head portion 72. A valve 132 cooperating with the port 128 is arranged to control the atmosphere connection 130 to the head portion 72 and is also provided with a valve stem having a forked member 134 having a roller 136 cooperating with a cam 138 fast on the central supporting sleeve. A similar spring 122 is arranged to urge the valve 132 to its open position. During the filling operation the cam 120 effectsopening of the valve 112 to permit the bag to be evacuated'and the material withdrawn from the supply through the inlet opening 74 into the bag. The space within the shroud is also evacuated at this time through a conduit connection 140 from the head portion 72 to an opening in the shroud to equalize the pressure within and without the flexible bag during the filling operation. Substantially simultaneously with the opening of the valve 112, the cam 138 effects closing of the atmospheric valve 132, the cams 120, 138 being arranged to effect alternate opening and closing of the valves subjecting the filling head alternately to the suction and the atmosphere during the filling operation.

Referring now to FIGS. 4 and 5, in accordance with the present invention, novel bag operated pneumatic control means is provided for initiating the filling operation and for controlling the operation of the machine in the event of displacement or absence of a bag. As herein shown, the control means includes a pivotally mounted sensing arm 142 which extends laterally into the filling head at a point above the shroud sealing portion 92, the inner end of the arm having a recessed element 144 arranged in the path of the upper edges of a fully seated bag in the filling head. The arm 142 is mounted on a stud 146 carried by a bracket 148 secured to the underside of the annular supporting plate 80. A second arm 150 extending at right angles to the arm 142 is arranged to cooperate with a sensing valve unit 152 having an operating arm 154 which carries a roller 156 engageable with said second arm. The sensing valve unit 152 forms a part of the pneumatic control circuit for controlling the cylinder 115 which operates the valve 110, the valve unit 152 being normally closed and arranged to be opened by the sensing arm 142 when the latter is rocked upwardly by the upper edge of a fully seated bag.

As illustrated in FIG. 4,.each sensing circuit, one of which is diagrammatically indicated at 160, includes a conduit 162 extending fromaheader' which latter is connected by a pipe to a tee170,"the upper endiof which is provided witha normally open pilot valve 172 and'the lower end'ofwhich is provided with a normally closed pilot valve 174. The pilot valves 172,174 are supplie'diwith. air from conduit connections 176, 178 from the conduit 1162and are connected by conduitls 180, 182 respectively tothe'upper andlow'efend 9f the two-way air cylinder 115. It will be observed that in operation when the valve 152 is closed, airisdir'e'cted from conduit 162 through the normally open" pilotvalve 172, and conduit 180 tothe upper end of the,cylinder'l15 to urge the valve 110 down to close the opening 1001c cut off. the vacuum supply to the filling head. vHowever, when the bag is fully seated. in its shroud and the arm 144 is rocked upwardly by the top edged the bag, the valve 152; is opened and air is directed through conduit 168 and tee 170 to close the normallyopenvalv'e 172 and open the normallyv closed valve. l74. As a result, the valve 110, is elevated to uncover-the ope'ning 100to afford commu-' nioation between the vacuum chain'bersf98 and ,102 to initiate "the fillingoperation. During continued rotationiof the filling head, thecam operated valves ll2, 1.32 are operated alternately as above described to complete the filling operation."

Subsequently, whentl eelevator is'lowered with its tilledbag,

the valve 152 isclos'ed ahd the pilot valves 172,-.174return to I their normal position to effect closing of the valvell0 to discontinue the fillingioperatio'n.

[From the description Qthusjfar, it will be apparent thatno bag-is present in, theishroud, orifvthe bag is 'notelevated to its fully seated position, indicating that it is crushed or crumpled within the shroud, thesensing valve 152 willnotbeopened, and the filling operation will vnot be initiated. In accordance with another-feature of the presentinventionjprovision is made for discontinuing the operationxof' the machine in the filling unit arrives, at the position where the switch 198 is located. The switch 198 is thus located to effect stopping of the machine to present the filling head at a convenient location when the machine comes-to rest to permit the'operator easy access to the filling headto remove the crumpled bag.

Provision is also, made for stopping the machine in the event that the filled bag is no t lowered with itselevator' at the end of a normal'fillingcycle. It will be seen that when a bag to be filled is fully, seated the valve 152 opened, the switch earns will be melted to the right as shown in FIG. 4, in which position 'cam 196 is rocked into a'position to open switch 200unless the switch cams are returned to their normal position. It will also be seenthatat the end of a normal filling cycle when the filled bag is lowered with its elevator, the sensing valve 152 will again be closed causing the cams 196, 192 to be again shifted so as to rocklcam196 out of alinement with switch 200 .and thus avoidstopping of the machine. However, if the bag fails to be withdrawn with its elevator indicating that thebag is stuck in its shr0ud,'the valve 152 will remain in its open-position so'that the earns 1.96, 192 will remain in :the'position shown in FIG. 4' to operate switch 200 thus opening the circuit to the motor starter coil 202 tostop the machine. While the 7 switch 200 is shown in FIG. 2 in a position removed from the position where the elevator starts its downward movement, it will be understoodthat-switchcam unit 196, 192'associated with the particular filling head under discussion is located in a position to engage the switch 200 when failure of a bag to. drop with its elevator is detected. When the machine comes to rest and the operator-manually withdraws the bag from'the shroud,

the valve 152 is againclosed and the switch cams are again rocked to their normal position.

event that a bag is not fully elevated into the shroud As diagrammatically illustrated in FIG,4, theconduits 180,182 con- I nected between the cylinder 115 and 'the normally open and normally closed'valves 172,174, respectively, are connected by conduits 184, 18,6tothe upper and lowenendsof-a two-way air cylinder 188 whosepis-ton rod190-iseonnected toa switch I As above described, a valve unit is associatedwith each elevating unit, each valve having an inlet connected by a conduit 210 leading fromthe header 73and'an ontletconnected bythe conduit 85 leading to the supporting post 66 on which the cylinder or sleeve 64 is mounted. The valve 71' is also provided 'withan operating arm .81 having'a roller 83 arrang'edto cooperate with cam 212 mounted at the end of a piston rod 214 operating in an air cylinder 216. Compressed air is supplied toithe-cylind'eriby apipe 218 leading from a normally supply of compressed airby a pipe 222.

opensolenoid valve 220, the valvelalso being connected. to a In operation, the cam 2l2'is normally extended, as shown, to-effect rocking of the arm 81 and opening of the valve 71 to cause-elevation ofa platform and initiate a filling operation cam l9 6vbeingdalinie'd with a stationary switch 200. The I switches 198, 200 maybe mounted on the'machin e frame and,

as shown in FIG. ,4, the switches are included in acircuit toa motor starter coil 2 02. ,lnfoperation, when the bag fails to be elevated into theishroudand the valve l 52 rerna ins closed, air

is directed from conduitfl62, conduit '1-76;'throughthe.normally open pilot'valve 172,;cjonduits 18'0 andil 84 t o the upper end of the air cylinder 188 to effect rocking ofthe switch cams to the left to position the dam 1-92 in alinement with the stationary switch-1 98..At-the same time, cam -196 is rocked, Out of I alinement with 'switch200.f."As"a result, when the valve 152 fails to be opened because. f a'c'r umpled bag, the'cam 192will operate switch 198' to sfopth'e machine.

On the other'hand, when the ba g is fully-seated so asto open the valve 152 and torcver -sc theloperationof'the'pilotvalves,

air is directed from conduits 162,178, pilot valve- 174 and conduits 182, 186 to the lower end of the two-way air cylinder 188 to effect rocking of 'the switch vcamsto the right. As a,

pathof the switch result, the earn 192 will be rocked out ofthe 198 and the machine will notbe stopped. v,

It will be understjqodthat there are a pair of'cams 196, 192

associated with each filling head. The positions of thesta'tiona-.

ry switches 198, 20031 the circularjpath of movement ofth'e filling heads is, showni'nFlG. 2. Althoughthe'cams 196, 192

are rocked to switch openingposition in case'of failure to open valve 152as, soon asthe elevator reaches its uppermost position, the-switch l98 will not be opened until the particular ma'tic elevation of the platform 10 is controlled by a stationary earn 246 andthe loweringof'the' platform 'is controlled by a earn 248, eachcarn cooperating with a'roller 250 carried by each sleeve or cylinder 64 of theelevating units,

In accordance with another feature of the invention, provi-. 'sion ismade for detecting the presence of a bag entering the machine-and forjpreventing elevation of a platform in the event that abag is missing from the line of spaced bags enter inggthe machine, such detecting means comprising a I photoelectric control indicated generally at 226 arrangedlto close the-normally open solenoidoper'ated'valve '220soas-to permit the air cylinder216 to exhaust, thus retracting the nor mally. extended cam 212. Opening of the valve 71 is thus prevented and the elevating platform remains in its loweredposition. As diagrammatically indicated in FIGS. 2 and 4, the

photoelectric control 226 for detecting the absence of a bag includes a light source 228 and a photocell230 connected to a photoelectric relay 232. The light source 228 is located below the-container supporting disk, and the latter is provided with 1 an opening 234 throughwhich the beam from the light source is directed to the photocell when a bag is missing, the beam being cut off by the presence of a bag. It will be noted that the -position of the opening 234 in the transfer mechanism for detecting an incoming bagis such that a continuously moving bag in such position will be transferred onto the continuously moving elevating platform numbered 1 when the latter arrives at the bag receiving position. Provision is made forenergizing the photocell 230 in timed relation to the movement of the bag, that is, the photocell is arranged to transmit signals only at times when a bag should be in the position to be detected, these signals being blocked during intervals between bags. As herein shown, the timing is accomplished by a normally open switch 236 connected to the photoelectric relay 232, the switch being arranged to be closed by the high spots of a cam 238 secured to and rotatable with the shaft 240 on which the discharge mechanism 22 is mounted.

From the description thus far, it will be seen that in operation if a bag is absent at the opening 234 the photoelectric relay 232 will energize the normally open solenoid valve 220 to close the same, thus retracting the air operated cam 212 and preventing opening of the valve 71 so that the elevator platform 10 remains in its lowered position. Since the elevator does not rise, the air valve 152 is not opened and a filling operation will not be initiated. Under ordinary conditions, when-the valve 152 remains closed, the air operated cam members 196, 192 are not rocked so that the cam 192 in alinement with switch 198 would effect stopping of the machine. However, since it is not necessary tostop the machine when a bag is absent, provision is made in such event for maintaining the motor circuit closed when the switch 198 is opened. This is accomplished by a cam piece 242 secured to the elevator which is alined with a normally open switch 244 when the elevator remains in its down position. The switch 244 is supported on the machine frame and is wired in parallel with the switch 198 so that when the normally closed switch 198 is opened by the cam 192, the elevator cam 242 effects closing of the switch 244 to maintain the circuit closed until after switch 198 is again closed.

From the above description it will be seen that the present vacuum filling machine is provided with novel container operated control mechanism including a pneumatic control circuit having a trip element extended within a filling head arranged to be engaged by the upper edge of a fully seated bag," said pneumatic control circuit having a sensing valve actuated by said trip element to initiate a filling operation. It will be seen that failure of a bag to be elevated into its fully seated position will not actuate the sensing valve and as a result a filling cycle will not be initiated. Provision is also made in response to failure of the sensing valve to be actuated for discontinuing operation of the machine so that the bag which failed to be fully elevatedmay be removed.

It will also be seen that failure of a filled bag to be lowered with its elevator from the filling head will maintain the sensing valve actuated and that in such event provision is also made for terminating the operation of the machine so that the struck bag may be removed. Finally, it will beseen that novel provision is made for detecting the absence of a bag in the supply of spaced bags being delivered to the machine, and that means responsive to the absence of a bag is arranged to prevent elevation of a bag supporting platform and thus prevent actuation of the sensing valve so that a filling cycle will not be initiated. it will also be seen that the elevating platform which failed to be elevated will continue in its lowered position throughout the cycle, and that provision is made for preventing termination of operation of the machine when a bag is initially absent from the line and the elevating mechanism is maintained in its lowered position.

While the preferred embodiment of the invention has been herein illustrated and described, it will be understood that the invention may be embodied in other forms within the scope of the following claims.

lclaim:

1. In a continuously operated rotary vacuum filling machine, in combination, vacuum filling means including a plurality of vacuum filling heads, a plurality of elevating platforms cooperating with said filling heads for supporting flexible bags, pneumatically operated means for-elevating the platforms to present the bagsinto operative relation to their respective filing heads, and pneumatically operated control means associated with each filling head including an air circuit and a container operated sensing valve in said air circuit having a movable actuating member cooperating therewith arranged to be engaged by the upper edge of said flexible bag to effect opening of the valve when the bag is elevated to its fully seated position in its filling head for actuating said vacuum filling means to initiate a filling operation, said actuating member adapted to be moved into operative engagement with said valve by a minimum of pressure exerted by the edge of the flexible bag, said vacuum filling means including a cylinder operated vacuum valve in said air circuit associated with its filling head, and a pair of pilot valves in said air circuit cooperating with said cylinder, said bag sensing valve con trolling said pilot valves to effect operation of the vacuum filling means to initiate the filling operation when the bag is fully seated.

2. In a continuously operated rotary vacuum filling machine, in combination, vacuum filling means including a plurality of vacuum filling heads, a plurality of elevating platforms cooperating with said filling heads for supporting flexible bags, pneumatically operated means for elevating the platforms to present the bags into operative relation to their respective filling heads, and pneumatically operated control means associated with each filling head including an air circuit and a container operated sensing valve in said air circuit having a movable actuating member cooperating therewith arranged to be engaged by the upper edge of said flexible bag to effect opening of the valve when the bag is elevated to its fully seated position in its filling head for actuating said vacuum filling means to initiate a filling operation, said actuating member adapted to be moved into operative engagement with said valve by a minimum of pressure exerted by the edge of the flexible bag, wherein said pneumatically operated control means includes a cylinder operated vacuum valve in said air circuit associated with each filling head, and a pair of pilot valves in said air circuit cooperating with said cylinder, said bag sensing valve controlling said pilot valves to effect operation of the vacuum filling means to initiate the filling operation when the bag is fully seated, said air cylinder comprising a two-way cylinder and the pilot valves including a normally open and a normally closed valve connected to the two-way air cylinder, said vacuum valve being closed to render the filling means inoperative when the sensing valve is closed, opening of said sensing valve effecting reversal of operation of said pilot valves to effect opening of the vacuum valve and initiation of the vacuum filling operation.

3. In a continuously operated rotary vacuum filling machine, in combination, vacuum filling means including a plurality of vacuum filling heads, a plurality of elevating platforms cooperating with said filling heads for supporting flexible bags, pneumatically operated means for elevating the platforms to present the bags into operative relation to their respective filling heads, and pneumatically operated control means associated with each filling head including an air circuit and a container operated sensing valve in said air circuit arranged to be opened by the bag when the latter is elevated to its fully seated position in its filling head for actuating said vacuum filling means to initiate a filling operation including drive means for rotating said vacuum filling means, said drive means including an electric circuit and a motor in said circuit, a normally closed stationary switch in said circuit, and switch operating means carried by each filling means and controlled by said sensing valve arranged to cooperate with said switch, said sensing valve in its closed position arranged to dispose said switch operating means in a position to open said switch to discontinue the circuit to the motor in the event that a bag is not elevated to its fully seated position in its filling head.

4. In a continuously operated rotary vacuum filling machine, in combination, vacuum filling means including a plurality of vacuum filling heads, a plurality of elevating plata forms cooperating with said heads for supporting flexible bags, pneumatically operated means for elevating theplat forms to present the; ,bags into operativevrelation to their respective fillingheads, and pneumatically operated control means associated with each filling'head including an air circuit and-a'container. operated sensin'gvalve in said-air circuit arranged'to be opened by the bag when the latter is elevated to and a container operated' sensing valve in said air circuit arrangedto be opened by the bag when the latteris elevated to its fully seated position in its filling head for'actuating said vacuum filling means to initiate'a filling operation, said pneuits fully seated position'ih itsvfi llingheadfor actuating said vacuumfilling means to initiatet a filling operation including drive means for rotating said vacuum filling means, said drive means including an electric circuit and a motor in said'circuit,'- a normally closed stationary switch in said circuit, .and a movable switch operating cam associated with each filling head and controlled bysaid sensing valve ,to dispose thefc'am out of operating alinement with said switch when'a .bag is fully seated in its filling head, ,saidcai'n remaining in its alinedposition to 1 open said switch to discontinue the circuit to the motor in the event that the bag is not fully-elevated into its filling head.

5. In a continuously "operated rotary vacuum :filling machine, in combination, vacuum filling meansuinc luding a t, plurality of vacuum filling'heads, a plurality ofgelevating plat-- forms cooperating with said filling headsfo'r supportin'gflexn ble bags, pneumatically operated means-for elevating theplatforms to presentthe bags into operative relation to their respective filling heads, andpneumaticall'y operated control 7 means associated with each filling head including'an air circuit and a container operated sensingval ve said air circuit'an' ranged to be opened bythe-bag when thelatter is elevated toits fully seated position in its filling headfor actuating said vacuum filling means toinitiate afilling operation including; drive means for rotating said vacuum filling means, said drive a forms cooperatingwith saidfilling headsforsupporting'flexible bags, pneumatically operated me'ans-for'elevating the plattor valve, means arranged in the path of said elevator valve. for

machine, in combination, vacuum filling-means including a Q plurality of vacuum filling heads, aplurality o'fxelevating plat? forms to present the bagsinto operative relation to their respective filling heads, and pneumatically .operated'control means associated with each filling headincluding an air circuit and a containeroperated sensing valve. insaidiair circuit ar, ranged to be'opened by the bag when the. latter is elevated to its fully seated position in its filling headfor actuatin g'said i vacuum filling means'to initiatea ,filling, operation" including drive means for, rotating saidvacuum filling means, said drive means including an electric circuitand amotor.insaidcircuit, a normally closedstationary switch in said circuit; a movable switch operating caniassociat'ed with each filling head,- means including an air cylinder in said air circuit controlledby said matically operated elevating means including an air supply "and an elevator valve associated with each elevator to admit air to effect elevation ofa platform when the valve is opened and to release air to permit" lowering of the platform when the valve-isclosed, means normally positioned to open said elevator valve, means arranged in the path of said elevator valve for closing the same at they end of a filling operation, means for detectingthe presence of a bag being delivered to an elevating platform, and means responsive to said detecting means for changing the-position of said elevator valve opening means to prevent opening of said elevator valve when a bag is found to be absent whereby to prevent elevation of said elevating platform."

8.;"In a continuously operated rotary vacuum filling machine, in combination, vacuum filling means including aplurality of-vacuum" filling heads,'a.plurality of elevating platforms cooperating withsaid filling, heads for supporting flexible bags, pneumatically operated means for elevating the platforms totpresent the-bags into operative relation to their respectivefilling heads, and pneumatically operated control means associated with each-filling-hea'd including an air circuit and'a container operated sensing valvein, said air circuit arranged'to'be opend bythe bag when the latter is elevated to its fully'seated position in it's filling head foractuating said vacuum fillingmeans to initiate a filling operation, said pneumatically operated elevating means including an air supply and an elevator valve "associated with each elevator to admit air to effect elevation of a platform when the valve'is opened and-torelease air to permit-lowering of the platform when the valve is closed, meansnormally positioned to open said elevaclosing the same atthe end of 'a'filling operation, means for detecting'the-presence of abag being deliveredlto an elevating platform, and means responsiveito said detecting means for changing the position of said elevator valve opening means to prevent opening of saidelevatorvalve whenia bag is found to be-absent whereby to prevent elevation of saidelevating platform, 'said elevator valve opening means including an air circuit, a cylinder operated .cam in said air circuit, a normally open solenoid operated valve in said air circuit, said solenoid operated valve also forming a part of an electrical circuit, said detecting means-including-an electric eye and a relay in said electricc'ircuit for closing said solenoid operated valve to permit bleeding ofsaid cylinder and retractionof said cam to prevent-opening of; the elevator, valve whena-bag is found to,

be-absent. t V a '9. ln 'a continuously operated rotary vacuum filling -r'nachine, in combination',-.vacuuin filling means including a sensing valve for moving its caminto operating'alinement with said switch when thesensing-valve is opened upon elevation of a bag into its fully seated position; said air,.cylindereffecting movement of the camoutofalinement with its switch'upon; 1 lowering of a filled bag with elevating'platform and-closing pluralityof vacuumtfilling heads, a plurality-of elevating plat- .forms cooperating-with said filling heads-for supporting flexiv ble bags, pneumatically operated means for elevating the platformsjtopresent the bags into operative relation to their respective filling heads, and pneumatically operated control means associated with each filling head including an air'circuit and a container,operated'sensing valve .insaid air circuit arof said sensing valve, said sensing valveremaining -in itsopen position to maintain its'cam inswitch opening position in the event that a filled bag fails tobe lowered with :its'elevating platform. M v Q i In a continuously operated rotary "vacuum filling 7. machine, in combination, vacuum filling means including a plurality of vacuumfilling-heads, a plurality of elevatingjplatforms cooperating'with said filling heads for supporting flexible bags, pneumatically operatedmeans forelevatin g the platforms to present the bags into operative relation totheirrespective filling heads, and pneumatically operated control means associated with eacl' filling hea'd including an air circuit ranged to be opened by the bag when the latter ,isielevated to its fully seated positioninitsfilling head for actuating said vacuum filling means to initiate a filling operatiomsaidpneumatically operated elevating means including an airsupply and an'elevator valve associated with each elevator to admit air to effect elevation of a-platform when the valve is opened and to release air to permit lowering of'the platform when the valve is-closed,means normally positioned to open said elevator valve,means arranged in the path of saidelevator valve for closing the same at the end of afilling operation, means for detectingthe presence of a bag being delivered to an elevating platform, and means responsive to said detecting means for changing the position of said elevator valve opening means to prevent opening of said elevator valve-when a bag is found to ing said shunt switch to prevent opening of the motor circuit when the elevator is initially maintained in its lowered position because a bag is absent, said normally open shunt switch remaining closed until said normally closed switch is returned to its normally closed position whereby to permit the machine to continue in operation with the elevator in its lowered position. 

